Rope structure



June 6, 1967 E, H. JACKSON, JR 3,323,301

ROPE STRUCTURE Filed Dec. 17, 1964 FIG. l-

INVENTOR.

Edward 11'. Jackson Jr,

United States Patent 3,323,301 ROPE STRUCTURE Edward H. Jackson, Jr., Box 162, RD. 4, Reading, Pa. 19606 Filed Dec. 17, M64, Ser. No. 419,014 4 Claims. (Cl. 57144) ABSTRACT OF THE DISCLOSURE A rope structure in which natural and synthetic fibers, or yarns, are combined, or twisted together, in such relative proportions and in such manner that both the natural and synthetic core and cover forming rope components will rupture simultaneously at substantially the same transverse area of the rope when it is subjected to a stretching force that will cause it to break.

This invention relates to ropes, or rope structures, that are composed of natural and synthetic fibers and that are more particularly adapted for marine use, as well as heavy duty uses in general.

Ropes have heretofore been provided which consist of nautral and synthetic fibers, or yarns, that are combined, or twisted together, in accordance with one arrangement or another, so as to impart to the rope one attribute or another. However, to my knowledge, no prior art rope of this type has been devised which solves the problem of simultaneously embodying therein a plurality, or combination, of attributes that will endow the rope with such highly desirable qualities or characteristics as maximum strength and longevity, substantial imperviousness from deterioration, as Well as maximum rope structure efficiency that is predicated upon substantially simultaneous breaking, or rupture, or both its natural and synthetic fiber components.

One object of my invention is to provide a novel rope, or rope structure, which solves the indicated problem.

Another object is to provide such a rope which has certain structural and functional features of advantage over the similar ropes of the prior art.

A further object is to provide such a rope which consists of natural and synthetic fiber, or yarn components, that are combined in substantially equal volume and in such manner as to endow the rope with certain qualities and characteristics of a superior order not heretofore attained by the similar prior art ropes, and at a comparatively lower production cost than the latter.

Another object is to provide such a rope which comprises a core component consisting of substantially all synthetic fibers and a cover component consisting of substantially all natural fibers.

An additional object is to provide such a rope having a core component of yarns consisting substantially entirely of high tenacity polypropylene fibers, such as presently marketed under the name of Tennessee Eastman Polypropylene, and having a cover component of yarns consisting substantially entirely of Manila, or of all sisal fibers.

Another object is to provide such a rope which comprises a synthetic fiber yarn core component and a natural fiber yarn cover component, which components have a stretch break factor, or ratio relationship, in the order of substantially one-to-one.

It is also an object to provide such a rope having a core component consisting substantially entirely of synthetic yarns of the type formed from high tenacity synthetic fibers, which fibers have a stretch break factor in the order of about six percent of their original length, and which rope has a cover component consisting substantially entirely of natural fiber yarns the natural fibers of which have a normal stretch break factor in the order of about three percent of their original length.

Another object is to provide such a rope which comprises, a core component substantially composed of synthetic fiber yarns, and a cover component substantially composed of natural fiber yarns, the yarn masses of said components being substantially equal in volume and forming inner and outer rope components having a stretch break ratio relationship in the order of about one-to-one, so that both of said components will rupture substantially simultaneously at the same transverse rope area when a particular rope section is stretched to its breaking point.

With these and other objects in view, which will become apparent from the following detailed description of the practical and illustrative embodiments of my improvements shown in the accompanying drawings, my invention comprises the novel rope, or rope structure, elements, features of construction and arrangement of parts or components in cooperative relationship, as more particularly indicated and defined by the hereto appended claims.

In the accompanying drawings:

FIGURE 1 is a somewhat enlarged side elevational view which more or less schematically depicts one form of multiple strand rope, or rope structure, in accordance with my invention.

FIGURE 2 is a view which is similar to FIG. 1, but which more or less schematically shows a single strand rope, or rope structure, in accordance with my invention, stretched to its breaking, or rupture point, at which both the synthetic fiber yarn core component and the natural fiber yarn cover component separate substantially simultaneously.

FIGURE 3 is a vertical cross-sectional view, taken substantially as indicated by the arrows 33 on FIG. 1.

It will facilitate an understanding of my invention to first briefly consider some of the more important aspects and phases thereof, so that these may be kept in mind when subsequently reading the detailed description of the practical and illustrative embodiments thereof depicted by the drawings.

Accordingly, it is noted that the rope, or rope structure of my invention, combines and utilizes the qualities and characteristics of certain natural fibers and certain high tenacity synthetic fibers, in such manner as to achieve a novel and superior rope structure that attains the indicated and other advantages and results.

The various attributes of my invention are substantially attained with a single strand rope, such as illustrated by FIG. 2, that embodies the unique improvements here involved, or with a rope which includes two, three or more component rope strands, or units, such as illustrated by FIGS. 1 and 3, that are structurally and functionally similar to the single strand rope of FIG. 2 and are twisted together to form a multiple strand rope structure.

For purposes of illustration, I have consequently herein shown and described two unique forms of rope structure, namely, a multiple strand rope structure which comprises three similar individual rope strands that are combinedly twisted together to form a hingle heavy duty rope, as

shown by FIGS. 1 and 3, and a single strand heavy duty rope structure, as shown by FIG. 2. From this disclosure, it will be apparent to those skilled in this art, how my invention can be practiced to advantage in various ways and also, that my invention is not limited in its scope to the specific form of ropes, or rope structures, herein disclosed.

Referring now particularly to the structurally more simple rope, or rope structure, of my invention illustrated by I IG. 2 of the drawings, the single strand rope there shown is generally identified by the letter R.

The rope R comprises a lengthwise extending core formation, or inner rope component 1, that is surrounded by a lengthwise extending cover formation, or outer rope component 2.

The rope core component I is composed of yarns 3 that are produced in accordance with the standard commercial practice, but consist entirely of high tenacity synthetic fibers, such as polypropylene fibers of the type presently being marketed under the name of Tennessee Eastman Polypropylene and having a normal stretch break factor in the order of about six percent of their original length. Such yarns, when formed into the core component I, will impart to the latter a normal stretch break factor in the order of about eight percent of its original length.

The rope cover component 2 is composed of yarns 4 that are likewise produced in accordance with the standard commercial practice, but consist entirely of natural fibers, such as Manila or sisal fibers having a normal stretch break factor in the order of about three percent of their original length. Such yarns, when formed into the cover component 2, will impart to the latter a normal stretch break factor also in the order of about eight percent of its original length.

Thus, the rope core components 1 and 2, when united, or combined, to form the rope structure of my invention, have a stretch break factor, or ratio, of about one-to-one.

In the rope structure R, the synthetic fiber yarn mass, or volume of the core component 1, is substantially equal to the natural fiber yarn mass, or volume of the cover component 2. This substantially equal mass arrangement of the high tenacity synthetic core yarns and natural fiber cover yarns serves to provide the rope R with various desirable qualities or characteristics. For example, it will endow the rope R with the outward appearance of a conventional Manila rope that is easily visible under all conditions of light, as well as endow the rope with a high degree of all the other well known desirable qualities and characteristics of a Manila rope. Furthermore, this arrangement will endow the rope R with a high degree of the special strength, light weight, imperviousness to moisture and erosion by the elements, and all the other well known and highly desirable qualities and characteristics of the high tenacity synthetic yarns 3 of the core component 1, at the reduced cost effected by the inclusion of such comparatively cheaper synthetic yarns. In addition, the said arrangement provides substantially maximum efiiciency of the rope structure R in that, due to the one-to-one stretch break factor, or ratio, that exists between the rope core component 1 and the rope cover component 2, both of these components, when unitedly stretched approximately eight percent of their original length, will separate, break, or rupture substantially simultaneously, at a transverse area, or Zone of greater stretch stress, or strain applied to the rope, as indicated at B in FIG. 2.

Referring next to the multiple strand rope of my invention illustrated by FIGS. 1 and 3, the heavy duty rope there shown is generally identified by the reference character M.

The rope M comprises three lengthwise extending, twisted together rope strands R R and R which individually are in all structural and functional respects like the single strand rope R shown in FIG. 2. In order to avoid redundancy of descriptive matter, the yarns and components of the three similar rope strands R R and R of the rope structure M that are visible in FIGS. 1 and 3 and correspond with the yarns and components of the single strand rope R, are identified by the same reference characters, but with the exponent a added for purposes of differentiation. In the rope structure M, as in the rope structure R, all of the rope components will separate, break, or rupture, substantially simultaneously, at a transverse area, or zone of greatest stress or strain applied to the rope, as previously pointed out in connection with the description of FIG. 2.

The single strand rope R, and the multiple strand rope M, are produced by well known prior art rope making machinery and in accordance with the standard commercial rope manufacturing practice. As usual, a plurality, or multiplicity, of the synthetic high tenacity polypropylene fibers, or filaments, are first combinedly twisted together to form the yarns 3, or 3*, to a suitable thickness or diameter. In like manner, the natural fibers, or filaments, are combinedly twisted together to form the yarns 4-, or 4 The said yarns are then properly arranged and combined in a usual yarn feeding and twisting apparatus capable of simultaneously twisting the yarns together so as to form one or the other of the rope structures R, or M, in accordance with the usual specifications to effect a hard rope, or a soft rope, as desired, or required. It will be noted from FIG. 2 that the core yarns 3 are twisted together in the same direction as the cover yarns 4. This is preferable for best results in accordance with my invention.

Modifications Of course, the novel rope improvement specifically shown and described, can be changed and modified in various ways without departing from the invention herein disclosed, the scope of which is more particularly indicated and defined by the hereto appended claims.

I claim:

1. A rope comprising a core component substantially composed of high tenacity polypropylene fiber yarns havmg a stretch break factor in the order of about six percent or their original length, and a cover component substantially composed of natural fiber yarns, said components containing substantially equal volumes of yarns and said components having a stretch break ratio relationship in the order of about one to one so that both components Will rupture substantially simultaneously at the same transverse rope area.

2. A rope comprising a core component substantially composed of synthetic fiber yarns and a cover component substantially composed of Manila fibers having a stretch break factor in the order of about three percent of their original length, said components containing substantially equal volumes of yarns and said components having a stretch break ratio relationship in the order of about one to one so that both of said components will rupture substantially simultaneously at the same transverse rope area.

3. A rope comprising a core component substantially composed of high tenacity polypropylene fibers having a stretch break factor in the order of about six percent of their original length, and a cover component substantially composed of Manila fibers having a stretch break factor in the order of about three percent of their original length, said components containing substantially equal volumes of yarns and said inner and outer rope components having a stretch break ratio relationship in the order of about one to one so that both of said components will rupture substantially simultaneously at the same transverse rope area.

4. A rope comprising a core component substantially composed of high tenacity polypropylene fiber yarns having a stretch break factor in the order of a percentage of their original length, and a cover component substantially composed of natural fiber yarns having a stretch 5 6 break factor in the order of a percentage of their original 2,591,628 4/ 1952 Snyder 57-140 length, said components containing substantially equal 3,201,930 8/ 1965 Stirling 57-140 X volumes of yarns, said stretch break factors of said yarns 3,205,649 9/1965 Nisbet et a1 57-440 of said inner and outer rope components, respectively, being in a ratio of about two to one whereby both said 5 FOREIGN PATENTS components will rupture substantially simultaneously. 811,501 4/ 1959 Great Britain.

891,618 3/1962 Great Britain. References Cited UNITED STATES PATENTS FRANK I. COHEN, Primary Examiner.

1,868,681 7/1932 Wyatt s7 152 X 10 D. E. WATKINS, Assistant Examiner. 

4. A ROPE COMPRISING A CORE COMPONENT SUBSTANTIALLY COMPOSED OF HIGH TENACITY POLYPROPYLENE FIBER YARNS HAVING A STRETCH BREAK FACTOR IN THE ORDER OF A PERCENTAGE OF THEIR ORIGINAL LENGTH, AND A COVER COMPONENT SUBSTANTIALLY COMPOSED OF NATURAL FIBER YARNS HAVING A STRETCH BREAK FACTOR IN THE ORDER OF A PERCENTAGE OF THEIR ORIGINAL LENGTH, SAID COMPONENTS CONTAINING SUBSTANTIALLY EQUAL VOLUMES OF YARNS, SAID STRETCH BREAK FACTORS OF SAID YARNS OF SAID INNER AND OUTER ROPE COMPONENTS, RESPECTIVELY, BEING IN A RATIO OF ABOUT TWO TO ONE WHEREBY BOTH SAID COMPONENTS WILL RUPTURE SUBSTANTIALLY SIMULTANEOUSLY. 